The 2D quality metric Peak-Signal-To-Noise-Ratio (PSNR) is often used when evaluating the quality of a coding schemes for integral imaging (II) based 3D-images. Either by applying the PSNR to the full II resulting in an accumulate quality metric for all possible views. Or by applying it to extracted sub-images, which results in a viewing angle dependent metric. However, both of these approaches fail to capture a coding scheme's distribution of artifacts at different depths within the 3D-image. In this paper we propose a quality metric that evaluates the quality of the 3D-image at different depths, which results in a 1D quality line. First, we introduce the metric and the operations that are used for its evaluation. Then the used experimental setup to evaluate the metric is presented. Finally the Second, it is evaluated on a set of IIs, coded using four different coding schemes. The preliminary results indicate a strong correlation with the coding artifacts that are visible at different depths.